ABSTRACT Slope exposure is one of the environmental factors that influences vegetation characteristics. Although there are studies on this aspect in various types of vegetation, up to now submontane shrublands have not been extensively studied. In this work, the effect of slope exposure on the structure and composition of plant species in a state park in northeastern Mexico where the dominant vegetation is submontane scrub was evaluated. Ten 10 x 10 m exposure sites were sampled: northeast, southwest and northwest. Total height (h), basal diameter (d 0.10) and crown diameter (k) were measured for each individual. Our hypotheses were: 1) the northwestern exposure community will have greater basal area, canopy cover, volume, absolute abundance, and specific richness due to higher humidity, 2) each slope will present dissimilarity in species composition. As results, nine families, 17 genera and 17 species of vascular plants were recorded. Fabaceae was the best represented family with six species. The species with the highest importance value index were the endemic shrub Neopringlea integrifolia in the northeast exposure (21.52 %) and the exotic tree Leucaena leucocephala in the southwest (16.17 %) and northwest (27.16 %) exposures. It is concluded that the plant community of the northwest exposure has a greater basal area, crown cover, volume, absolute abundance and specific richness. However, there was no real difference in the species composition of the three exposures.

RESUMEN La exposición de ladera es uno de los factores ambientales que influye sobre características de la vegetación. Aunque existen trabajos sobre este aspecto en diversos tipos de vegetación, hasta ahora los matorrales submontanos no han sido muy estudiados. En este trabajo se evaluó el efecto de la exposición de las laderas en la estructura y composición de especies de plantas en un parque estatal del noreste de México donde la vegetación dominante es matorral submontano. Se muestrearon 10 sitios de 10 x 10 m en exposición: noreste, suroeste y noroeste. A cada individuo se le midió la altura total (h), diámetro basal (d 0,10) y diámetro de copa (k). Nuestras hipótesis fueron: 1) la comunidad de la exposición noroeste tendrá mayor área basal, cobertura de dosel, volumen, abundancia absoluta y riqueza específica debido a la mayor humedad, 2) cada ladera presentará disimilitud en la composición de especies. Como resultados se registraron nueve familias, 17 géneros y 17 especies de plantas vasculares. Fabaceae fue la familia mejor representada con seis especies. Las especies con mayor índice de valor de importancia fueron la arbustiva endémica Neopringlea integrifolia en la exposición noreste (21,52 %) y la exótica arbórea Leucaena leucocephala en las exposiciones suroeste (16,17 %) y noroeste (27,16 %). Se concluye que la comunidad vegetal de la exposición noroeste tiene mayor área basal, cobertura de copa, volumen, abundancia absoluta y riqueza específica. Sin embargo, no hubo diferencia real en la composición de especies de las tres exposiciones.

Abstract INTRODUCTION Urinary tract infection is the second-leading reason for consults in primary health care. Bacterial urinary tract infections are the most common, of which Escherichia coli is the main etiologic agent. Antimicrobial resistance and multidrug resistance complicate effective community treatment, especially if resistance is caused by extended-spectrum beta-lactamase production. WHO recommends that antimicrobial susceptibility be evaluated in different regions of the world at different times. Community-acquired E. coli’s susceptibility to colistin has not yet been studied in Cuba, and mcr-1 gene screening is necessary. OBJECTIVE Evaluate community-acquired uropathogenic E. coli isolates’ susceptibility to antibiotics, including colistin, and identify extended-spectrum beta-lactamase–producing bacteria. METHODS We conducted a descriptive cross-sectional study that included 281 community-acquired uropathogenic E. coli isolates (153 from the Isle of Youth Special Municipality’s Hygiene, Epidemiology, and Microbiology Center and 128 from Microbiology Laboratories of 7 institutions in Havana) from June 2016 through July 2018. We used the disk diffusion method to determine susceptibility to ampicillin, ampicillin/sulbactam, cefazolin, trimethoprim/sulfamethoxazole, ciprofloxacin, nitrofurantoin and fosfomycin. The disk elution method was used to determine susceptibility to colistin. The combined disk method was used to identify extended-spectrum beta-lactamases. Estimates were made regarding the frequency and percentages of antimicrobial susceptibility and resistance, as well as multidrug-resistance patterns. RESULTS Of the 281 isolates, 68.3% (192/281) were resistant to ampicillin, 54.8% (154/281) were resistant to ciprofloxacin, and 49.5% (139/281) were resistant to trimethoprim/sulfamethoxazole. Resistance to colistin was not detected. On the other hand, 14.2% (40/281) were susceptible to the 8 antibiotics we evaluated, 22.1% (62/281) showed resistance to only 1 antibiotic, and 63.7% (179/281) were resistant to 2 or more antibiotics. In the extended-spectrum beta-lactamase determination, 34.5% (97/281) had inhibition zones ≤14 mm with cefazolin. Of those with inhibition zones, 64.9% (63/97) were positive in the phenotype test, and 35.1% (34/97) were negative. In extended-spectrum beta-lactamase–producing bacteria, 1.6% (1/63) were resistant to fosfomycin, and 3.2% (2/63) were resistant to nitrofurantoin. The most common multidrug-resistance pattern (22.9%; 30/131) was to ampicillin/sulbactam, ampicillin, cefazolin, ciprofloxacin, and trimethoprim/sulfamethoxazole. CONCLUSIONS Uropathogenic E. coli resistance to the antibiotics most frequently used in community medical practice is quite common, and extended-spectrum beta-lactamase–producing bacteria is the mechanism for beta-lactam antibiotic resistance. Multidrug-resistance patterns include resistance to the antibiotics most used in community-acquired infections. Fosfomycin and nitrofurantoin are the most active in extended-spectrum beta-lactamase producing bacteria. All the isolates were susceptible to colistin.